WASHINGTON -- Sixty Republican national security heavyweights vow in an open letter released late Wednesday to work “energetically” to prevent GOP front-runner Donald Trump from winning the party's nomination.

The experts, who represent vastly divergent GOP ideologies, d escribe Trump's vision of American influence as “wildly inconsistent and unmoored in principle.” They warned that a Trump presidency would “make America less safe” and “diminish our standing in the world.”

The letter was organized by Eliot Cohen, a former State Department official, and Bryan McGrath, a former Mitt Romney adviser. It was released the day after Trump won seven states on Super Tuesday, stoking his momentum and giving fresh urgency to a NeverTrump movement of Republican officials working against him.

In just 454 words, the letter signatories eviscerated Trump for his “expansive use of torture,” his “hateful, anti-Muslim rhetoric,” and his expressed admiration for Russian President Vladimir Putin. They slammed his proposal to require Mexico to build a wall on its border with the U.S. and accused him of behaving more like a “racketeer” than a dependable ally for suggesting that Japan pay for military protection. They accused Trump of holding an amorphous worldview -- switching from isolationism to interventionism, and refusing to acknowledge his past support for the 2003 U.S.-led invasion of Iraq and the 2011 intervention in Libya.

“We accept that views evolve over time, but this is simply misrepresentation,” they wrote in the letter, signed by several people who backed the Iraq war and who favored supporting the opposition fighters in Libya.

Some on Twitter mocked the signatories for taking a stand only after Trump’s Super Tuesday victories. But some signers have long been raising alarm over Trump’s candidacy.

Max Boot, a senior fellow at the Council on Foreign Relations and an adviser to rival GOP candidate Sen. Marco Rubio (R-Fla.), has been bashing Trump on Twitter long before the #NeverTrump movement made it safe to do so. Former State Department official Robert Kagan wrote a scathing article last week blaming the Republican Party for quietly embracing the same bigoted sentiments that Trump has espoused. Philip D. Zelikow, an attorney who headed the commission charged with uncovering what went wrong in the leadup to the Sept. 11 attacks, shut down Trump’s claim in December that the hijackers sent their wives to Saudi Arabia before the attacks.

The letter represented a rare consensus from a disparate group of people. For example, former Pentagon adviser Matthew Kroenig is an outspoken critic of the Iran nuclear deal and has called for a military attack on Iran again and again. But Tufts University’s Daniel Drezner has long challenged the long-term strategic wisdom of a military strike on Iran and has acknowledged the nonproliferation benefits of the nuclear deal, while expressing skepticism about its regional implications.

The 60 signers pledged not to support the Republican ticket in the November elections if Trump ends up as the nominee, effectively killing any chance of a high-level Trump administration job for any of them. McGrath told The Washington Post this doesn’t mean the signers would defect from the GOP and vote for the Democratic nominee, but some of his colleagues admitted to Politico they felt they had no other choice.